This manual provides suggestions for investigating simple machines and the teaching of certain basic concepts which pertain to them. Many of the lessons are designed to be used with the commercially available LEGO kits, in an effort to teach concepts in a way in which students must translate pictures shown in two dimension into three-dimensional models. The guide lists the scientific concepts and principles being addressed, along with the unit objectives and other materials which are needed. The major portion of the guide describes 12 lessons, which deal with: (1) an introduction to the simple machines unit; (2) work and levers; (3) friction; (4) inclined planes and screws; (5) wheels and axles; (6) belt transmission (as it applies to multiplying force and speed); (7) gears and gear ratios; (8) the transmission of motion; (9) centrifugal force and motion; (10) pulleys; (11) steering mechanisms; and (12) mechanical advantage. Included is a set of test items that can be used for evaluating student progress. (TW)